1 /* 2 * Copyright (c) 2014 Google, Inc 3 * 4 * SPDX-License-Identifier: GPL-2.0+ 5 */ 6 7 #include <common.h> 8 #include <dm.h> 9 #include <errno.h> 10 #include <fdtdec.h> 11 #include <malloc.h> 12 #include <spi.h> 13 #include <dm/device-internal.h> 14 #include <dm/uclass-internal.h> 15 #include <dm/root.h> 16 #include <dm/lists.h> 17 #include <dm/util.h> 18 19 DECLARE_GLOBAL_DATA_PTR; 20 21 static int spi_set_speed_mode(struct udevice *bus, int speed, int mode) 22 { 23 struct dm_spi_ops *ops; 24 int ret; 25 26 ops = spi_get_ops(bus); 27 if (ops->set_speed) 28 ret = ops->set_speed(bus, speed); 29 else 30 ret = -EINVAL; 31 if (ret) { 32 printf("Cannot set speed (err=%d)\n", ret); 33 return ret; 34 } 35 36 if (ops->set_mode) 37 ret = ops->set_mode(bus, mode); 38 else 39 ret = -EINVAL; 40 if (ret) { 41 printf("Cannot set mode (err=%d)\n", ret); 42 return ret; 43 } 44 45 return 0; 46 } 47 48 int spi_claim_bus(struct spi_slave *slave) 49 { 50 struct udevice *dev = slave->dev; 51 struct udevice *bus = dev->parent; 52 struct dm_spi_ops *ops = spi_get_ops(bus); 53 struct dm_spi_bus *spi = dev_get_uclass_priv(bus); 54 int speed; 55 int ret; 56 57 speed = slave->max_hz; 58 if (spi->max_hz) { 59 if (speed) 60 speed = min(speed, (int)spi->max_hz); 61 else 62 speed = spi->max_hz; 63 } 64 if (!speed) 65 speed = 100000; 66 if (speed != slave->speed) { 67 ret = spi_set_speed_mode(bus, speed, slave->mode); 68 if (ret) 69 return ret; 70 slave->speed = speed; 71 } 72 73 return ops->claim_bus ? ops->claim_bus(dev) : 0; 74 } 75 76 void spi_release_bus(struct spi_slave *slave) 77 { 78 struct udevice *dev = slave->dev; 79 struct udevice *bus = dev->parent; 80 struct dm_spi_ops *ops = spi_get_ops(bus); 81 82 if (ops->release_bus) 83 ops->release_bus(dev); 84 } 85 86 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, 87 const void *dout, void *din, unsigned long flags) 88 { 89 struct udevice *dev = slave->dev; 90 struct udevice *bus = dev->parent; 91 92 if (bus->uclass->uc_drv->id != UCLASS_SPI) 93 return -EOPNOTSUPP; 94 95 return spi_get_ops(bus)->xfer(dev, bitlen, dout, din, flags); 96 } 97 98 int spi_post_bind(struct udevice *dev) 99 { 100 /* Scan the bus for devices */ 101 return dm_scan_fdt_node(dev, gd->fdt_blob, dev->of_offset, false); 102 } 103 104 int spi_child_post_bind(struct udevice *dev) 105 { 106 struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev); 107 108 if (dev->of_offset == -1) 109 return 0; 110 111 return spi_slave_ofdata_to_platdata(gd->fdt_blob, dev->of_offset, plat); 112 } 113 114 int spi_post_probe(struct udevice *bus) 115 { 116 struct dm_spi_bus *spi = dev_get_uclass_priv(bus); 117 118 spi->max_hz = fdtdec_get_int(gd->fdt_blob, bus->of_offset, 119 "spi-max-frequency", 0); 120 121 return 0; 122 } 123 124 int spi_child_pre_probe(struct udevice *dev) 125 { 126 struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev); 127 struct spi_slave *slave = dev_get_parentdata(dev); 128 129 /* 130 * This is needed because we pass struct spi_slave around the place 131 * instead slave->dev (a struct udevice). So we have to have some 132 * way to access the slave udevice given struct spi_slave. Once we 133 * change the SPI API to use udevice instead of spi_slave, we can 134 * drop this. 135 */ 136 slave->dev = dev; 137 138 slave->max_hz = plat->max_hz; 139 slave->mode = plat->mode; 140 141 return 0; 142 } 143 144 int spi_chip_select(struct udevice *dev) 145 { 146 struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev); 147 148 return plat ? plat->cs : -ENOENT; 149 } 150 151 int spi_find_chip_select(struct udevice *bus, int cs, struct udevice **devp) 152 { 153 struct udevice *dev; 154 155 for (device_find_first_child(bus, &dev); dev; 156 device_find_next_child(&dev)) { 157 struct dm_spi_slave_platdata *plat; 158 159 plat = dev_get_parent_platdata(dev); 160 debug("%s: plat=%p, cs=%d\n", __func__, plat, plat->cs); 161 if (plat->cs == cs) { 162 *devp = dev; 163 return 0; 164 } 165 } 166 167 return -ENODEV; 168 } 169 170 int spi_cs_is_valid(unsigned int busnum, unsigned int cs) 171 { 172 struct spi_cs_info info; 173 struct udevice *bus; 174 int ret; 175 176 ret = uclass_find_device_by_seq(UCLASS_SPI, busnum, false, &bus); 177 if (ret) { 178 debug("%s: No bus %d\n", __func__, busnum); 179 return ret; 180 } 181 182 return spi_cs_info(bus, cs, &info); 183 } 184 185 int spi_cs_info(struct udevice *bus, uint cs, struct spi_cs_info *info) 186 { 187 struct spi_cs_info local_info; 188 struct dm_spi_ops *ops; 189 int ret; 190 191 if (!info) 192 info = &local_info; 193 194 /* If there is a device attached, return it */ 195 info->dev = NULL; 196 ret = spi_find_chip_select(bus, cs, &info->dev); 197 if (!ret) 198 return 0; 199 200 /* 201 * Otherwise ask the driver. For the moment we don't have CS info. 202 * When we do we could provide the driver with a helper function 203 * to figure out what chip selects are valid, or just handle the 204 * request. 205 */ 206 ops = spi_get_ops(bus); 207 if (ops->cs_info) 208 return ops->cs_info(bus, cs, info); 209 210 /* 211 * We could assume there is at least one valid chip select, but best 212 * to be sure and return an error in this case. The driver didn't 213 * care enough to tell us. 214 */ 215 return -ENODEV; 216 } 217 218 int spi_find_bus_and_cs(int busnum, int cs, struct udevice **busp, 219 struct udevice **devp) 220 { 221 struct udevice *bus, *dev; 222 int ret; 223 224 ret = uclass_find_device_by_seq(UCLASS_SPI, busnum, false, &bus); 225 if (ret) { 226 debug("%s: No bus %d\n", __func__, busnum); 227 return ret; 228 } 229 ret = spi_find_chip_select(bus, cs, &dev); 230 if (ret) { 231 debug("%s: No cs %d\n", __func__, cs); 232 return ret; 233 } 234 *busp = bus; 235 *devp = dev; 236 237 return ret; 238 } 239 240 int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode, 241 const char *drv_name, const char *dev_name, 242 struct udevice **busp, struct spi_slave **devp) 243 { 244 struct udevice *bus, *dev; 245 bool created = false; 246 int ret; 247 248 ret = uclass_get_device_by_seq(UCLASS_SPI, busnum, &bus); 249 if (ret) { 250 printf("Invalid bus %d (err=%d)\n", busnum, ret); 251 return ret; 252 } 253 ret = spi_find_chip_select(bus, cs, &dev); 254 255 /* 256 * If there is no such device, create one automatically. This means 257 * that we don't need a device tree node or platform data for the 258 * SPI flash chip - we will bind to the correct driver. 259 */ 260 if (ret == -ENODEV && drv_name) { 261 struct dm_spi_slave_platdata *plat; 262 263 debug("%s: Binding new device '%s', busnum=%d, cs=%d, driver=%s\n", 264 __func__, dev_name, busnum, cs, drv_name); 265 ret = device_bind_driver(bus, drv_name, dev_name, &dev); 266 if (ret) 267 return ret; 268 plat = dev_get_parent_platdata(dev); 269 plat->cs = cs; 270 plat->max_hz = speed; 271 plat->mode = mode; 272 created = true; 273 } else if (ret) { 274 printf("Invalid chip select %d:%d (err=%d)\n", busnum, cs, 275 ret); 276 return ret; 277 } 278 279 if (!device_active(dev)) { 280 struct spi_slave *slave; 281 282 ret = device_probe(dev); 283 if (ret) 284 goto err; 285 slave = dev_get_parentdata(dev); 286 slave->dev = dev; 287 } 288 289 ret = spi_set_speed_mode(bus, speed, mode); 290 if (ret) 291 goto err; 292 293 *busp = bus; 294 *devp = dev_get_parentdata(dev); 295 debug("%s: bus=%p, slave=%p\n", __func__, bus, *devp); 296 297 return 0; 298 299 err: 300 debug("%s: Error path, credted=%d, device '%s'\n", __func__, 301 created, dev->name); 302 if (created) { 303 device_remove(dev); 304 device_unbind(dev); 305 } 306 307 return ret; 308 } 309 310 /* Compatibility function - to be removed */ 311 struct spi_slave *spi_setup_slave_fdt(const void *blob, int node, 312 int bus_node) 313 { 314 struct udevice *bus, *dev; 315 int ret; 316 317 ret = uclass_get_device_by_of_offset(UCLASS_SPI, bus_node, &bus); 318 if (ret) 319 return NULL; 320 ret = device_get_child_by_of_offset(bus, node, &dev); 321 if (ret) 322 return NULL; 323 return dev_get_parentdata(dev); 324 } 325 326 /* Compatibility function - to be removed */ 327 struct spi_slave *spi_setup_slave(unsigned int busnum, unsigned int cs, 328 unsigned int speed, unsigned int mode) 329 { 330 struct spi_slave *slave; 331 struct udevice *dev; 332 int ret; 333 334 ret = spi_get_bus_and_cs(busnum, cs, speed, mode, NULL, 0, &dev, 335 &slave); 336 if (ret) 337 return NULL; 338 339 return slave; 340 } 341 342 void spi_free_slave(struct spi_slave *slave) 343 { 344 device_remove(slave->dev); 345 slave->dev = NULL; 346 } 347 348 int spi_slave_ofdata_to_platdata(const void *blob, int node, 349 struct dm_spi_slave_platdata *plat) 350 { 351 int mode = 0; 352 353 plat->cs = fdtdec_get_int(blob, node, "reg", -1); 354 plat->max_hz = fdtdec_get_int(blob, node, "spi-max-frequency", 0); 355 if (fdtdec_get_bool(blob, node, "spi-cpol")) 356 mode |= SPI_CPOL; 357 if (fdtdec_get_bool(blob, node, "spi-cpha")) 358 mode |= SPI_CPHA; 359 if (fdtdec_get_bool(blob, node, "spi-cs-high")) 360 mode |= SPI_CS_HIGH; 361 if (fdtdec_get_bool(blob, node, "spi-half-duplex")) 362 mode |= SPI_PREAMBLE; 363 plat->mode = mode; 364 365 return 0; 366 } 367 368 UCLASS_DRIVER(spi) = { 369 .id = UCLASS_SPI, 370 .name = "spi", 371 .flags = DM_UC_FLAG_SEQ_ALIAS, 372 .post_bind = spi_post_bind, 373 .post_probe = spi_post_probe, 374 .child_pre_probe = spi_child_pre_probe, 375 .per_device_auto_alloc_size = sizeof(struct dm_spi_bus), 376 .per_child_auto_alloc_size = sizeof(struct spi_slave), 377 .per_child_platdata_auto_alloc_size = 378 sizeof(struct dm_spi_slave_platdata), 379 .child_post_bind = spi_child_post_bind, 380 }; 381 382 UCLASS_DRIVER(spi_generic) = { 383 .id = UCLASS_SPI_GENERIC, 384 .name = "spi_generic", 385 }; 386 387 U_BOOT_DRIVER(spi_generic_drv) = { 388 .name = "spi_generic_drv", 389 .id = UCLASS_SPI_GENERIC, 390 }; 391